Improvement in low-water indicators for boilers



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CHARLES S.WA'I`SON,l PHILADELPHIA, PENNSYLVANIA.

Letters Patent No. 103,690, dated May 3l, 1870; antedatetl Jan/nary 29, 1870.

, IMPROVEMENT IN LOW-WATER INDICATORS FOR BOILERS.

The Schedule referred to in these Lettera Patent; and making phart of the same.

To all whom 'it may concern tach it to the head of the boiler, as usual, as it can be arranged at any convenient point adjacent to or at a distance from the boiler, and even, if desirable, 1n a separate apartment.

In order to enable others skilled in the art to make and apply my invention, I will now proceed to describe its construction and operation, reference being had to the accompanying drawing, which forms a part ot this speciiication, and'in which- Figure 1. is a sectional view of my improved lowwater indicator. for steam-boilers, and

Figures 2 and 3, detached views of the same, drawn to an enlarged scale.

A represents a cylindrical metal casing, closed a the top by a screw-plug, b, and connected, at its lower end, to a tube, X, (shown by red"lines, iig. 1,) which communicates with a steam-generator, and projects downward into the same to the'lowwater line. l

At one side of this casing is a hollow projection, a, having, at the top, a threaded branch, c, into which is screwed a plug, D, formed at the lower end Vof aA steam-whistle, F, of ordinary construction, the plug D heilig recessed, for the reception of a valve, e, adapted to a seat, f, and retained in its seat by means of a conical spring, h, which rests upon a ledge, i, of the plug, and bears against the under side of' the said valve. y

The valve e is provided with a stem, e', which projects below the vlower end of the plug D; and

to a pin, y', at a point beneath this valve-stein, is hung a lever, H, connected at one end to a sheetmetal cup, L, open at the top, while at its oppo- Vsite end there is an enlargement, k, of suic-ient weight to counterbalance and` raise the said cup, as seen in iig. 1.

The lever H is provided with a lug or dog, m, which, as long as the cup L remains elevated, is free iiom contact with the valve-stem e', but which, when the said cup descends, is arranged to strike and turn the valve-stem laterally, as shown in tig. 3, slightly compressing the spring h, and opening the valve e suiiiciently to permit steam to pass, between the same and its seat, to the whistle, as will be here after described.

'lhe operation of the apparatus is as follows: W'hen the water is at'a proper height in the boiler, the lower open end of the tube X is submerged in thesame, and the water, owing to the pressure within the boiler, iills the said tube, as well as the whole interior ot' the indicating apparatus, as seen iu iig. 1.

So long as the apparatus remains thus filled with water, the weight k will maintain the cup L in an `elevated position, and the lug m free from contact with the valve-stem e; but, should the water in the boiler descend to a .point below the end of the tube'X, steam will enter the latter, and will pass upward through .the same into the apparatus, the water, as it is displaced, returning, through the tube X, into the boiler.

lhe cup -L will, however, remain' filled with water, and this addition to its weight will enable it to counterbalance the weight k, and to descend and turn the lever H to such au extent that the lug'm shall strike and turn the valve-stem e', thus causing the valve e to be opened suiiciently to permit steam w to pass into and blow the whistle F, and warning the attendant of the low condition otthe water in the boiler.

On replcnishing thel boiler, the pressure of steam will again cause the water to rise through the tube X, and ll the apparatus, the steam within the lat.- ter either becoming condensed, or passing oli' through the whistle F, until the valve e is closed, on the releasing of the stem by the falling of the weight k and corresponding rising of the cup L. Y

In apparatus of this class, as heretofore constructed,

it has been customary to have two points of com-` munication with the boiler, in order that the water admittedA into the vapparatus may be maintained at precisely the same level as that within' the boiler.

It is essential, also, that such 'apparatus should be placed at a point level with and adjacent to the boiler, which requirements render their use, in many instances, extremely inconvenient.

llhis objection I have overcome entirely in my improved indicator by having but one point of connection with the boiler, namely: through the tubc X, which plan enables Ine to place the apparatus at any convenient point, either adjacent to or remote from the boiler, and even, if desired, in a separate apartment.

Amongthe other advantageous features of my inrprovement may be mentioned its simplicity and its Aregular automatic action".;

Inasmuch as the stem of thevalve e is in a vertical position,. the valve is not liable to be drawn from its seat, as is the case when the stem is inclined or horizontal.

I claim as my invention, and. desire to Letters Patent- 1. The cup or vessel L, lever H Weighted at one end, valve c, and casing A, combined and arranged substantially as here'in described.

2. The casing A, with its projections a and c, and

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